US2876001A - Regulating device for braking system in printing presses - Google Patents

Description

March 3, 1959 s, STENSTROM 2,876,001

REGULATING DEVICE FOR BRAKING SYSTEM IN PRINTING PRESSES Filed Sept. 6, 1955 2 Sheets-Shem; 1

fi 5 SQOOCTFOOOOOOOCO%O I ..V i ll 4 =1: fi T16 I a 26 37 1; if

INVENTOR fie/2E fliewirazrg,

BY Jmmd-M A ORNEYS United States Patent REGULATING DEVICE'FOR BRAKING SYSTEM 7 IN PRINTING PRESSES In printing presses of the reciprocating type-bed kind it is generally known to use air bufier cylinders for braking purposes in order to take up the work which the type bed must emit during its reversing movements if operation of the press is to be reasonably free from vibration.

As the mass forces originating from movement of the type bed varies with the square of the speed, the braking device should be so designed that the work taken up by the air bufier cylinders varies in proportion to same.

It has been possible to obtain practicable results within limited speed ranges by placing diaphragm valves in the brake pistons. Closing of these valves, as is well known, is somewhat dependant upon the air velocity and, therefore, the piston will enter the brake piston to different depths at varying speeds before the diaphragm valve closes and compression is started. r

If, however, greater variationsof speed are involved theremust be a possibility of much greater variations in the work taken up. For an example, may be mentioned, it a press is run at a speed of 4000 prints per hour, the turning forceof the type bed will amount to a maximum of 4000 kgs., for instance. This force, or rather the work performed by this force, in the above example, is taken up by an air buffer having an area of about 400 cm. which means a specific pressure of kg./cm. If, on another occasion, the same press is run at a speed of only 2000 prints per hour, the maximum turning force will be only 1000 kgs., corresponding to a final pressure of only 2.5 kg./cm. Variations of this magnitude, however, cannot be overcome by using diaphragm valves.

At present 3000 prints per hour may be regarded as the top speed that could not be exceeded on account of the vibrations, to which the press would be subjected. This, of course, being based on the assumption that there are certain regulating facilities within the speed range. a

An object of the present invention is to provide a regulating device for the braking system of printing presses of this kind which will permit an increase in speed of the press to above 4000 prints per hour for the same size of press with no disturbing vibrations arising and with a maintained possibility of good speed regulation with the entire speed range. .This invention is principally characterized in that the brake cylinder is; cylinders is or are connected bymeans of pipe lihes with one or several regulating cylinders, in which a piston is movable so as to be moved against the action of a spring to one of two predetermined positions by the compressed air generated in the brake cylinder or cylinders, and to be secured automatically there by a locking device.

In the accompanying drawings an'illustrative embodiment of the invention is represented.

In the drawings, 7 I

Figure 1 is a diagrammatic end view of a printing press stand provided with two brake cylinders and having a regulating device according to this invention connected with the brake cylinders of the press.

. Patented Mar. 3, 1959 Figure 2 is a diagrammatic side view of a press equipped according toFigure 1.

Figure 3 is a longitudinal sectional view through a regulating device according to this invention with the parts adjusted for one rate of speed of operation of the press.

Figure 4 is a view similar to Fig. 3 with the parts adjusted for a different speed of operation of the press.

Figure 5 is a diagram showing the work taken up by the braking device at two different printing speeds, with the regulating piston adjusted in positions A and B corresponding to same.

In the accompanying drawings numeral 1 designates a regulating device mountedon the stand 2 of a two. revolution printing press-having a reciprocating type bed 3. The press is provided with two brake cylinders 4and 5.

In the diagrammatic representation of the press and regulating system, members of the press which are not directly involved in the details of the present invention are identified as follows. Numeral 3 designates the reciprocatory type bed; 32 indicates the type bed roller racks; 33 indicates the type; and 38 indicates the impression cylinder of the press..

The regulating device as shown, in Figs. 3 and 4 cornprises a cylinder 7 enlarged and in longitudinal section 7 having a piston S therein which is provided with packing. rings 9, the said pistonbeing movable longitudinally in said cylinder 7 so as to have its inner face 10 in one of two different positions A or B. The position of the parts when adjusted for a higher speed of operation of the press is represented in Fig. 3, while that for a slower speed of operation is shown in Fig. 4. As shown in Figs. 3 and 4 the piston 8 is fitted with a piston rod 11, around which a spring 12 is arranged in such a manner that it tends to push the piston 9 towards thebottom of the regulating cylinder, that is, toward the right in Figs. 3 and 4.

A locking ring 14, on piston rod 11, determines the front piston 21, 22 respectively, having heads 24 and 25 re-' spectively, provided by grooves 26, 27, respectively, extending therearound' near their upper ends. On the lock housing 15, a three armed locking lever 28 is pivotally mounted at 29. The locking lever has two arms 30 and 31 which extend in opposite directions from the pivotal mounting 29, which arms have their outer extremities pivotally connected with the locking pistons 21, 22, at 34 and 35, respectively; and the third arm 36 of said locking lever, which is approximately perpendicular to the two first-mentioned arms thereof is held either by spring 37, or a manually operable Bowden wire 39 in either of its end positions. Located within each of the tube-shaped pistons 21 and 22 is a locking rod 40, 41 respectively, these rods being longitudinally slidable in pistons 21 and 22. Rods 40 and 41 are provided with heads 42 and 43, respectively. Each of said heads is acted on vertically in both directions by sets of springs, 45, 46 respectively acting upwardly and 47, 48 respectivelyacting downwardly. Either the one or the other of the two locking rods 40 or 41 will, when in adjusted 7 The springs 45, 46, 47, 48 serve the following pur- 2 pose. In position A (Fig. 3), the locking piston 21 is in its lower position and spring 47 is pressing the locking rod 40 down into the recess 50 of piston rod 11. The o kin pistes Z2 s in i s p e Pos an Spring 46 is actuating the locking rod 41 so that this is lifted and held at the position shown out of engagement with iston Whenchanging to position B (Fig. 4) the lever 28 is turned to position corresponding to B, in which locking piston 21 is lifted to its upper position and spring 45 would l'ft locking rod 40 out of recess 50. When compressed air again enters cylinder 7 piston 9will move to the left against the pressure of, spring 12, until locking rod 41' engages in recess 50 under the influence of spring .6 Press n d wn a he eon- As appears from the above, the springs 47, 48 allow the lever? 28 tohe actuated independently of the actions and positlous of the locking pistons 21, 22 and the locking rods. 40, 41.

The positions A and Bof the piston (Figs. 3 and 4 respectively) correspond to, for-instance, printing press speeds of 40,00 and 3000 prints per hour, respectively. An impulse for changing the positions of the piston when changing from one speed to another is imparted to the system in such a Way thatthe three-armed lever by means of any suitable control device shown in the form of a Bowden type pull cable 39 in the direction indicated by theflarrow in Fig. 4, supported by bracket 54 on the lock housing. 15 is swung over to the opposite position rom #11 9 39- sh t in F Rcadjustrnent of the piston is then effected in the mannot described below.

If the press is operated at the higher speed, piston 8 will be in the position shown in Fig. 3, that is, position A. If it isdesired to change to a lower speed range, piston 8 is moved to position B (Fig. 4) it smooth running is to be obtained. By action upon lever arm 36 the threeearn ed lever 28 is swung over to its other end position. But this does not cause in itself, any change in the position of locking rods 42, 43. Locking rod 42 is held in position in recess 50 as long as spring 12 is permitted to act freely upon piston But when a brake piston 53 (Fig. 1) enters the brake cylinder 5, connected with the regulating device, increase of the pressure in fsont of the face of piston 8 will cause the latter to. be forced back, that is, to the left, in Fig. 3.

v Thereby brake t od 40 is freed and quickly pulled from recess 50 by itsspring 45. The 'piston 8 then continues its movement under the influence ofincreasing air pressure entering the regulating cylinder7 through pipe 6, to position shown in Fig. 4, when brake rod 41 by the influence of its spring 48, is forced down into recess 50 in piston rod 11, th e said recess beingnow right opposite the rod 41. To prevent piston 8 from beating against housing 15 a packing 35 is positioned therebetween.

Whenchanging piston=8 from position B (Fig. 4), to position A (Fig. 3), the force on lever arm 36 is released and the lever is swung back to its initial position by spring- 37. Lock-ing rod 40 is self-locking in recess 50 and does not leave sameuntil the compressed air acting upon thefface 10 ofpiston 8 over balances spring 12. When the pressure ;in cylinder 7 is released again, spring 12 forces piston 8 torwardto front position A (Fig. 3). At the same time, looking ring 14 contacts lock housing -15, a nd locking rod 42 descends into recess 50.

Depending upon conditions prevailing, one or several brake. cylinders, 4, '5, may be connected with the regulating apparatus 1.

In Fig. 5 of the drawing, the curve represented by letter A represents thework taken up by the braking devicewhen'the press is working at the higher speed and piston; isadjusted into position A (Fig. 3), while curve B represents the equivalent with the piston 8 in position B (Fig. 4).

By means of this invention, which may be varied within the scope of the claims appended hereto, smooth and uniform operation can befattained even at speeds that are considerably higher than those used so far.

I claim:

1. A regulating apparatus for reciprocatory type beds of printing presses, having a press frame, a type bed mounted thereon to be reciprocated in operation, a pair of oppositely facing brake pistons mounted on said bed to reciprocate therewith, a pair of brake cylinders located on said frame spaced apart and facing in opposite directions in positions to be entered by said brake pistons respectively, a brake regulating cylinder for each brake cylinder, conduit means connecting each of said brake cylinders with one of said regulating cylinders, respectively, the improvement comprising a spring in each of said regulating cylinders, a regulating piston in each of said regulating cylinders acted on by said springs respectively so as to be pressed axially of said cylinder in the directions toward the connections of'said conduit means with said regulating cylinder respectively, said conduit means being connected to said regulating cylinders in- Wardly of said pistons, so as to supply compressed air to said regulating cylinders from said respective braking cylinders to move said pistons against the force of said respective springs, and means for locking said pistons in one or another of two positions in said regulating cylinders adapting said regulating cylinders to have resistive pressure built therein at a higher or lower rate depending on the pos itio ns of said pistons and, thus, to alter the amount :of air admitted to said regulating cylinders in operation for serving difierent speeds of reciprocation of said type bed.

2. Apparatus according to claim 1, in which said means for locking said pistons comprise lock housings, two locking members in each of said housings spaced apart longitudinally or the direction of movement of said regulating pistons, a distance corresponding tothe proper position of said respective pistons in said cylinders for certain speeds of operation .of the press, a pair of springs for each locking member respectively, acting upon said locking members oppositely in the directions of their movements, said regulating pistons each having a longitudinally extending rod extending from said regulating cylinders respectively and provided with a recess to be entered by either of said locking members to lock said respective adjusting pistons in difierent'positions, said lock housing covering said regulating cylinder at the end from which said rod extends and means acting on said springs of said locking members respectively for actuating said locking members to locking or releasing positions.

3. Apparatus according to claim 2, in which said means for locking said pistons also comprises tube shaped pistons in which said springs are located and locking rods connected with said locking members, respectively and upon which said springs act, said locking rods extending outside of said tube shaped pistons to enter said groove in said rod of said regulating piston.

re e it d n the fi se i ten UNITED STATES PATENTS Germany June 25,

Images